Growing conditions in 2018 were the definition of a mixed bag. There was an excessively wet spring in parts of the Eastern Corn Belt, debilitating drought in Kansas and Missouri, and timely rains in Nebraska that have dryland corn holding its own against its irrigated brethren.
Despite the ups and downs, farmers are likely to harvest record, or at least near-record, corn and soybean crops this fall.
In mid-August, DTN/The Progressive Farmer completed its first ever Digital Yield Tour, powered by the data analytics firm Gro Intelligence. The goal was to gauge crop potential by comparing on-the-ground observations in 10 states with the latest yield forecasts from Gro’s models.
At the time, the models predicted a national average corn yield of 174.99 bushels per acre (bpa), along with an average soybean yield of 50.67 bpa. Gro’s models update on a daily basis. For more information on how they work, see “About the Gro Intelligence Yield Models,” on PF-7.
Both estimates came in below USDA’s August forecast, which called for a 178.4-bushel-per-acre average on corn and a 50.9-bpa average on soybeans.
DTN Senior Ag Meteorologist Bryce Anderson says widespread rain hit a broad swath of corn and soybean country after the Digital Yield Tour wrapped up, providing a potential boost to yield potential, especially on soybeans.
While the adage “big crops get bigger” could be true across broad swaths of the Corn Belt, for a few other states, the rain may have been too little, too late.
Illinois, Indiana, Iowa:
Illinois and Indiana are on pace to produce record corn and soybean yields. While Iowa’s crops aren’t expected to earn a place in the record books, Gro’s estimates call for another bin-buster.
Gro Intelligence yield estimates from mid-August indicate Iowa corn farmers will harvest 194.42 bpa, Illinois growers 203.53 bpa and Indiana producers 188.95 bpa. Iowa’s estimate is 7.5 bpa below USDA’s figures. Illinois’s estimate is also lower, but it’s still on track to beat last year’s record of 201 bpa. Indiana corn growers could be the only “I-state” to meet or exceed USDA’s projections.
On soybeans, Gro expects a state average yield of 56.53 bpa in Iowa, 59.70 bpa in Illinois and 57.21 bpa in Indiana. While they’re consistently lower than USDA, Illinois and Indiana would still be near historic records.
Of the I-state regions, central Illinois is expected to wear the crown. Chase Brown farms in Macon County, where Gro estimates the average corn yield at 218 bpa. Brown says his mid-August yield checks ranged from 230 to 245 bpa.
“We think the deciding factor this year will be population,” he says. “Those fields that took the worst of the stress in late May and early June may be only 16 (rows) around, but we’ve got the stands.” Planted at 35,000 plants per acre, stand counts indicated 34,000-plus remain, Brown explains.
Illinois’s bountiful crop prospects spread across the border into west-central Indiana, where Gro’s model indicates a sweet spot in Tipton, Carroll and White counties. A little further south, the summer’s heat helped offset a very wet spring.
“There’s nothing about 27 inches of rain in June that is normal,” Gibson County farmer Scott Wallis says. “When it was hot, we had lots of humidity, and that saved the crop. We probably have had two days all summer where the corn leaves rolled. I can’t say the same for myself--it was hot.”
In mid-August, Gro forecast the Gibson County soybean crop at just shy of 50 bpa, but Wallis says his farm’s five-year average is much higher, around 70 bpa. “I’m really excited about soybeans,” he says. “The pod count is simply incredible in the Group 3s.”
Iowa also had a wet spring, and some farmers didn’t finish soybean planting until July 4.
“We’re going to need a late frost in this area, as a lot of our beans have a ways to go,” says Jay Magnussen, who farms and works as an agronomist in O’Brien and Cherokee counties, in the northwestern section of Iowa. But, he adds that yield potential on them is in the 60-bpa or better category.
Nebraska, South Dakota:
Nebraska’s irrigated corn may get all of the notoriety for high yields, but this year, it’s the dryland crop fueling high expectations.
Gro Intelligence forecasts Nebraska corn farmers will harvest an average 191.33 bpa, while South Dakota growers will harvest an average 160.25 bpa. Both estimates are higher than last year’s totals but slightly below USDA’s August estimates.
On soybeans, Gro expects a state average of 59.36 bpa in Nebraska and 47.09 bpa in South Dakota. Like corn, both estimates are higher than last year but lower than USDA’s August forecasts.
“During the first and middle portions of summer, these two states were on the edge of oppressive hot and dry high pressure that covered the southwestern U.S., and were in line for active thunderstorm formation,” DTN’s Anderson says. “There was severe weather, as well, but the large majority of acreage had favorable rainfall.”
Nebraska farmer Randy Uhrmacher told DTN every time the forecast called for a 10-day hot-and-dry stretch, at least four days turned out cool and wet.
“I’m not going to say USDA is wrong,” he says, referencing the agency’s 196-bpa average corn yield estimate for the state. Uhrmacher farms in the corridor along Interstate 80 that shows some of the highest yield estimates in the state, with Gro forecasting average yields above 200 bpa for nine counties west of Lincoln in mid-August.
His operation spans Adams and Webster counties, where Gro forecasts average yields of 204.3 bpa and 172.48 bpa, respectively. The primary difference between the two: About 80% of the land in Adams County is irrigated, while 75% of Webster is dryland, Uhrmacher says.
Gro’s yield maps incorporate another set of maps, known as the normalized difference vegetation index (NDVI), which uses satellite imagery to show how abnormally dry or lush an area is using a 10-year average “greenness” index.
The map for South Dakota features a prominent scar from a cluster of hail damage in the central part of the state that occurred in mid-June. Gro estimates corn yields of 110 to 117 bpa in the hardest-hit areas, but estimates jump to the 130- to 140-bpa range in counties to the east of the storm damage. The state’s highest corn and soybean yield prospects are along the state’s eastern edge, where corn yields in Minnehaha and Moody county are expected to break 190 bpa, and soybean yields are forecast to top 50 bpa.
Late-August rains probably weren’t enough to revive pastures or save corn fields in drought-stricken parts of Kansas and Missouri, where much of the corn crop had already been chopped for silage.
During the Digital Yield Tour, Gro Intelligence predicted an average corn yield of 140.96 bpa in Missouri and 139.85 bpa in Kansas. While both of these estimates are significantly below last year, they are higher than USDA’s August estimates.
For soybeans, Gro has pegged Missouri’s average yield at 45.16 bpa and Kansas’s average soybean yield at 39.38 bpa. Both projections are near USDA’s August estimates.
In Kansas, the Gro’s yield maps highlighted an unusual trend: Crops in eastern Kansas were in worse shape than in the west, with county corn yield averages ranging from 83 bpa to 124 bpa in the southeast compared to higher yield estimates of 142 bpa to 211 bpa in the southwest.
“The western part of the state got some relief from rains in June and July that fizzled before they could help out the areas farther east,” Anderson says. “This rain-deficit sector has had the driest summer since the drought year of 2012.”
Over in northwest Missouri, where Bob Birdsell farms in Gentry County, Gro’s yield map suggests average yields will hover near 100 bpa. He says corn yields in his area start from zero, where some fields were abandoned or cut for silage.
“Heat and lack of rains have been our problems with corn and beans,” he says. “I think we may make APH [Actual Production History yield], but that’s 135 bushels.”
However, a slightly better picture emerges in a narrow diagonal corridor running from west-central Missouri up to the northeast corner of the state in Gro’s yield maps. The far southeastern corner of the state also fares better.
Minnesota, Ohio, Wisconsin:
It’s unlikely farmers in Minnesota and Wisconsin will repeat last year’s record-setting performance, but they still expect to harvest sizeable crops. In Ohio, farmers are looking at yields that are consistently larger than last year.
Gro Intelligence forecasts Minnesota corn farmers will harvest 190.73 bpa, Wisconsin growers 175.83 bpa and Ohio producers 182.33 bpa. Gro’s estimates for Minnesota and Wisconsin are both slightly lower than USDA’s August forecast, while Ohio’s estimate is higher by a couple of bushels.
On soybeans, Gro expects a state average yield of 49.98 bpa in Minnesota, 54.08 bpa in Wisconsin and 53.80 bpa in Ohio. Minnesota’s and Wisconsin’s estimates are higher than USDA, while Ohio’s is lower.
Mark Nowak, who farms in south-central Minnesota, says this year is no repeat of 2017.
“Last year’s record crop happened from a moist July and a below-normal August temp,” Nowak recalls. “So, the opposite is happening this year: drier July and above-normal August temp.”
He estimates that his corn crop in Faribault County will be down 8% from last year, which USDA pegged at 215 bpa in his county. Gro’s yield map agrees, suggesting corn yields in his region will hover around 200 bpa.
To the east of the Twin Cities in Wisconsin, Tony Mellenthin says he is concerned about kernel weight and pod fill. The corn crop got an early start and had pleasant weather during pollination, then it turned hot and dry. “It’s going to be difficult--I’m not going to lie--on corn because the corn kernels are there,” he says. “My concern is how heavy are these kernels going to be with this dry weather?”
The summer was also drier than normal in Ohio, but the temperatures were milder. Keith Peters says he expects corn yields in his central-Ohio counties to be “well above average,” which Gro yield maps confirm, pinning them around 188 bpa.
Overall, corn yields in Ohio look more uniform than last year’s, where the state pulled in a patchwork of yields across the western two-thirds of the state. This year, Gro’s yield maps show yields ranging more consistently from 163 to 197 bpa.
About the Gro Intelligence Yield Models:
Gro Intelligence’s modeling system is based on several types of publicly available crop and environmental data: vegetative health based on NASA satellite imagery; land surface temperature maps; rainfall data; USDA crop condition surveys; crop calendars; planted and harvested acreage data from the National Agricultural Statistics Service (NASS); cropland data; and U.S. government soil surveys.
Unlike other analytical models, which are fairly static, Gro applies machine learning methods to determine which variables carry the most weight at any particular time and adjusts as it goes forward. It also updates daily to incorporate the latest weather and crop condition data.
Gro builds its models from the county up, and, because it relies on satellite and a variety of other data, it produces yield estimates for counties that don’t garner enough survey response to be included in NASS estimates. County yield estimates inform statewide average yield estimates and national yield outlooks.
For the 2017 corn crop, Gro’s model estimated the national average yield at 176.86 bushels per acre (bpa) compared to USDA’s final tally of 176.6 bpa. The data analytics firm launched its corn yield model in 2016 and its soybean model in 2018.
For more information on the DTN/The Progressive Farmer Digital Yield Tour and how Gro Intelligence’s models work, visit www.dtn.com/digital-yield-tour-18 and Gro-intelligence.com.
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